Westland Wasp HAS 1: 'Ambuscade Flight: XT778'

[TheBaron]

With sleep patterns disrupted in recent weeks I was up in the middle of the night for the familiar ritual of a pot of tea and a sleepy pondering of books that can't be settled on.

 

Mainly though, thoughts kept drifting back to the utterly trivial matter of how a brake caliper might be fitted to the back of a helicopter gearbox. Possibly the only thing which this problem has going for it is that it is quite specificand can only have a very limited number of potential solutions. As no no stills photography had thus far given me enough confidence to take an informed guess, this inevitably turned into a detective story sifting through videos online in oder to see if they afforded that crucial glimpse - no matter how fleeting - which could lay the matter to rest.

 

On the evidence of last night, the 'Nimbus scene' seems to consist of a bunch of mad lads either letting their engines off in front of the neighbours or else dramatically engulfed in clouds of smoke.

 

Something almost heroic about it, in a quite bonkers way.

 

By a process of elmination I think I can say with some confidence now that there is nothing to the rear of the brake disc for the calipers to attach to, so they must be attached to  the gearbox somehow. This is a still from the definitive video source:

^{Image credit: Jettech7}

Such footage was in many cases of dire quality so this picture had to be washed through an AI program to clean it up for posting. You can clearly see that with the engine running and calipers on there's nothing this side of the brake disk to hold them in place. Another video here, - although seeming to have a  non-standard caliper attached - does give glimspes of some kind of attachment linkage to the rear of the gearbox, though never gets in at a useful enough angle to be a ble to work out the exact nature of it.

 

Given how concealed that fitting is in real life, this information was going to be enough for me to to be able to knock up a piece of brass PE that will serve to hold the calipers in place without striking a false note to the visuals of the area:

That quixotic shape is simply to allow it to be firmly atached  to the gearbox in the correct orientation, like so:

With the brake disk on, that fitting is as hidden as its real-life counterpart:

A couple of other modifications were also carried out at the same time. The exhausts hollowed out further back into the solid lump of the forks so as not to look too odd, as well as the inner facing profile of the calipers being corrected after I noticed that they aren't a squared-off box profile as I'd originally produced:

For printing purposes that gearbox will be split to match the seam lines of the real thing:

IYou're right that those locating lugs look oversize but I learned on the Vixen that wee ones tend to get lost amongst the printing supports and make clean-up a real pain. Some extra 'business' was also added forward of the gearbox where it disappears in through the forks to head off in the direction of  the turbine:

That top centre cylinder with curly edges overhanging the brake disc has a bracket and some gubbins to go on it stiil and then I'm calling that component finished (this side of plumbing and wiring it all up):

^{Image credit: Phil Defer}

 

Progress on the .stl library for the Nimbus to finish:

 

 

Take care until next time.

Tony

 

 

 

 

 

[Pete in Lincs]

Loon pants. Early seventies yes. They were cheap and fashionable but had no pockets! Ah well, I (thought I) was fashionable for a few months at least.

 

The mounting for the Callipers looks good to me. Or rather, it doesn't because it can't be seen! Well played Sir!

[Navy Bird]

On 03/11/2022 at 04:38, TheBaron said:

The important bit to this though - you spent an afternoon with Son House!!? That's one hell of an experience to look back on; blues revelations of any kind  - particularly Delta ones - are to be considered essential essential inputs on any of my threads at any time, for future reference.

 

Amazing experience (he even let me drink from his malt liquor bottle). Son was "rediscovered" in 1965 living in my hometown, and when I read about this in 1970 I had to meet him. I looked for his number in the phone book and it was listed so I rang him up. What an audacious 16 year old! And what a cool old guy and storyteller he was - I have no clue if any of it was true but does that matter? He was in early stage Alzheimer's I think, but reasonably coherent. I got to sing along with John the Revelator! I'll never forget it. Here's his autograph (I remembered to bring a pen but not a camera! Just as much of a moron as I am today):

 

 

Cheers,

Bill

 

PS. Back to outrageous CAD work!

[giemme]

Neat solution on that fitting, Tony! Hat's off!

 

Ciao

[perdu]

That fabrication, in the sense of a device for doing a job rather than as a bit of a fib, must be very close to the actual device on the Nimbus Tony.

When I saw your challenge yesterday I spent my day fruitfully and examined every photograph I own of Scout and Wasp, both pictures we've no doubt both gleaned from the web and some of Wasp and Scouts I took myself never web published.

 

Result?

 

Nada!

 

Hence I declare Tony's version to be the best, likeliest method of securing the calipers on the rotor brakes of Nimbus engine transmission combos.

 

The best idea I could get was from AP101C-0601-34 Wasp Part B controls.pdf on page 101 of 111

 

Tells me absolutely nothing excepts it gives me confirmation of the roor brake's position in the cabin and that the calipers sit round the brake dicsc at the back.

 

I think in the interest of my OCD-ity I will put out a S.O.S to @bootneck for some kind of recce if he ever gets round to the Helicopter Museum any time soon, just fora heads-up on the taxing problem.

[perdu]

This is the best from my own pictures, zoomed in crudely from my phone, off my monitor on zoooooom.

[Pete in Lincs]

Marvin says "Life? Gimme a brake!"

[heloman1]

Liking the parts renders very much. Never worked on the Wasp, although we had one on 845 NAS aboard Bulwark '66 ish. IMS I think I painted a cartoon on the cockpit door.

 

Colin

[TheBaron]

19 hours ago, Pete in Lincs said:

They were cheap and fashionable but had no pockets! Ah well, I (thought I) was fashionable for a few months at least.

And cheap, apparently...

17 hours ago, Navy Bird said:

Amazing experience

 - and beautifully told Bill. Grateful for you sharing that treasure - I have Mr. House playing out loud in an empty house here as I write.

6 hours ago, giemme said:

Neat solution on that fitting, Tony! Hat's off!

I do like a mystery, even if it's not possible to resolve it entirely.... 😁

2 hours ago, perdu said:

That fabrication, in the sense of a device for doing a job rather than as a bit of a fib, must be very close to the actual device on the Nimbus Tony.

When I saw your challenge yesterday I spent my day fruitfully and examined every photograph I own of Scout and Wasp, both pictures we've no doubt both gleaned from the web and some of Wasp and Scouts I took myself never web published.

 

Result?

 

Nada!

Gah Bill! You're a pal for going digging like that!

2 hours ago, perdu said:

he best idea I could get was from AP101C-0601-34 Wasp Part B controls.pdf on page 101 of 111

Ditto - which made me rue the absence of p.101a....

 

2 hours ago, perdu said:

Hence I declare Tony's version to be the best, likeliest method of securing the calipers on the rotor brakes of Nimbus engine transmission combos.

Well, if that gets a vote of confidence from you Bill, then it's fair to say that I'm satisfied with yesterday's work then. 

 

If you asked me to put money on it anything this stage, my 50p would be on that 'D'-shaped tubular form  which the caliper is bolted to at each end (boxed in red here on your original) is somehow involved:

It's a specifically-shaped feature with no evident function but if the right hand one in this picture extended backwards toward the centre of the gearbox, it could in theory be bolted onto something. Would such a single mounting point be strong enough though given the forces involved when the caliper engaged?  I'm certainly not qualified to speculate....

 

Even it that was the actual means of support,  it would still be too fragile at this scale to replicate as a viable solution so  I'm covering my posterior by staying with the existing PE compromise...

1 hour ago, Pete in Lincs said:

Marvin says "Life? Gimme a brake!"

'I've been communicating with the ship.Wasp.'

'What did it say?'

'It says it wants more parts.'

 

Bracket, one of:

Plate and a (message garbled) connector:

Bracket, triangular:

Bracket, upright, octagon for the support of:

Octagon, thermocouples for the connection of:

Gearbox, motive force for the reduction of:

Assembled:

Portrayed:

Concludes:

 

Thank-you.

Tony

 

 

 

 

[TheBaron]

17 minutes ago, heloman1 said:

Liking the parts renders very much. Never worked on the Wasp, although we had one on 845 NAS aboard Bulwark '66 ish. IMS I think I painted a cartoon on the cockpit door.

 

Colin

Our messages must have crossed in the clouds Colin. Thanks for the kind words.

Can you recall what your painting was of?

[heloman1]

20 hours ago, TheBaron said:

Our messages must have crossed in the clouds Colin. Thanks for the kind words.

Can you recall what your painting was of?

 

20 hours ago, TheBaron said:

Our messages must have crossed in the clouds Colin. Thanks for the kind words.

Can you recall what your painting was of?

Hi, as far as a I can remember back to '66, that is was a three box cartoon maybe an Andy Capp. Further than that, it's a mystery, I really should have taken a photo.

 

Colin

[giemme]

On 04/11/2022 at 16:39, TheBaron said:

Concludes:

 

This is so spaceship!

 

Ciao 

[mark.au]

Dunno about spaceship but it’s definitely pro-level something.

[TheBaron]

At the risk of over-exciting people, I built some tubes and rectangles  recently.

On 05/11/2022 at 12:17, heloman1 said:

Further than that, it's a mystery, I really should have taken a photo.

😁

On 05/11/2022 at 18:15, giemme said:

This is so spaceship!

 

On 05/11/2022 at 20:53, mark.au said:

Dunno about spaceship but it’s definitely pro-level something.

 

 Now this is what I call a set of  exhausts....

^{Image credit: Chris Foss}

I should start by saying that I hadn't intended to do any of following bits yet as I was really intent on building the starter, the trumpet-like appendage that blares out along the stbd topside of the Nimbus. In the process of eyeing it up though I realized that there was still some significant work to do producing a correct profile for the section immediately behind the air intake, in order for it to look more Nimbous in shape:

Because it's not the most visible region of the engine on either side (due to intervening structures) I hadn't noticed the much more eleborate nature of that penultimate profile until now - particularly that sticky-out bit at the three o'clock position with is where the front ECU mount bolts it into place. So that's why no starter, as once I'd corrected that I immediately noticed a whole load of other consequences to do with how both the MRGB and her Nimbosity are bolted to the deck through common points.

 

Whilst there's a spatial elegance  in how they designed all these bits to go together, it's still a bit of a London Underground map working out how and in what way these structures interface with one another in three dimensions. This 'ere upright is the reason why I was horrified to discover an error in my MRGB design:

You can see here how that flared traingular section of the MRGB bolts onto it. Well, at the start of today's session my flared triangular bit didn't exend far enough out laterally to meet it, being  shy by a good 2mm. At least I've grown savvy enough to crudely block in shapes first of all in order to establish such critical meeting points - otherwise there would have been a lot to dismantle later on:

It came up short initially today because I actually had it right in my original design for that section of the MRGB and then a few weeks back thought it looked to extend out too far and so 'corrected' it inwards - a perfect example of how you should trust your visual instincts sometimes....or maybe just look a bit more closely before changing something!

 

Anyway, this upright is a sort for miniature 'Grand Central' for pylons which emante from the ECU, engine deck and MRGB. You can see that from the bit of iit which the MRGB bolts on to, that it's already gained two additional mounting brackets - one for a pylon  eextending out to spread the load of the engine to the side of the deck, and another pointing backward onto which is bolted the angled base of the forward ECU:

That base is deuced hard to see amidst the structural tangle around this region but luckily I had some critial high angle views and a decent drawing in the manual to correspond to one another. Here's the ECU mount itself that takes the load of the forward part of the Nimbus:

I added a couple of locating lugs at the bottom of it at either end to help position it securely in the base plate during assembly:

I know this kind of looks like one Cyberman being looking shocked by the other one smoking a cigar: that big Havana is a visual stand-in for a bit of 0.7mm brass tube that will allow the engine unit to plonk down securely at the correct height and alignment:

I haven't mirrored the base and upright across to port yet as there's still another bracket for the MRGB pylons to add to the ensemble and then I'll need to replicate the pylon ddesigns around the MRGB in a single operation, which will be 'interesting' enough a process that it'll keep until next time.

 

As this is 1/24th I can - in strength terms at least  - print a lot more of the pylons than would have been the case at smaller scale. I'd ummed and ahh'd a lot in recent weeks about how many of such features to build from resin as I've a passion for the brass that knoweth no bounds. Here I think the big pylons will be printed - partly from easily  creating a standardized part that can be replicated - but the smaller cfor rods and the rotor blade servos/linkages may well work better in terms of sharpness of feature as brass fittings. A closer inspection of the crow's nest will be required to look a the feasibilty of such intentions...

 

A couple of portraits of current progress to finish with tonight then:

 

A good evening to all of you.

Tony

 

 

Edited November 7, 2022 by TheBaron
Apparent illiteracy of the author...

[Pete in Lincs]

A complex conundrum indeed. Your 'use a bigger stick' approach is working well.

[bigbadbadge]

Exquisite renderings Tony, they look fantastic.  The brake disc calipers too and the gearbox are phenomenal.    

Great work 

Chris

[Brandy]

That looks as though some serious detective work was required there as they are not clearly visible in the pics you've shown so far.

They certainly look the part though!

 

Ian

[giemme]

Are we sure this is still a WASP, and not the Millenium Falcon?    

 

Impressive research and modelling work, Tony!

 

Ciao

[TheBaron]

Just occasionally it occurs to the non-modelling world that we may actually posses vital life skills after all (I've lost track of how many times the family has borrowed tools from my studio to repair something small and fiddly, with grudging admissions of utility). I managed to solder repairs to a favourite bracelet of my aged Mater's for her birthday at the weekend and she was delighted:

Was tempted to put some extra PE on as well but you know, you have to draw a line.

 

Immensely pleased to learn over the course of the last week also that people have been safely receiving their Vixen kits - in all candour I don't know when I've been more nervous about an undertaking! It's one thing to spend your days solving mysteries with a van and a talking dog but another level of nerve-shredding altogether meeting the expectations of expert modellers.

 

On 07/11/2022 at 19:25, Pete in Lincs said:

A complex conundrum indeed. Your 'use a bigger stick' approach is working well.

You know what they say about men with big sticks Pete.

Yep, it means they also have a huge-

-tree in the garden that is slowly dying and shedding wood everywhere before it eventually falls over onto their house.

On 07/11/2022 at 20:28, bigbadbadge said:

Exquisite renderings Tony, they look fantastic.  The brake disc calipers too and the gearbox are phenomenal.    

That's the glamorous jobs done now anyway Chris.

Back to metal cylinders again today I'm afraid...

On 07/11/2022 at 21:11, Brandy said:

That looks as though some serious detective work was required there as they are not clearly visible in the pics you've shown so far.

They certainly look the part though!

Thanks Ian!

You're dead right that it's a bit of a mare's nest around that part of the deck; loads of fittings and whatnot to obscure a visual reckoning. It's one of tthose particular situations where I find it really important to have a parts or maintenance manual to correspond with photography, there's nearly always something you can't quite see in its entirey and which the latter helps give you the confidence to proceed with on an informed basis.

On 08/11/2022 at 09:27, giemme said:

Are we sure this is still a WASP, and not the Millenium Falcon?

Mad isn't it G?

Makes you realize how adaptable kitbashing became for making the kind of model 'bigatures' used in scifi films when you see parts of something like the Wasp in abstract...

^{Image credit: The Prop Gallery}

Pretty sure I see a rotor brake in there.... 🤣

 

To business anyhow.

 

As Ian mentions, it not a straightforward proposition working out some of the angles an connections on the Wasp's engine deck:

In the latest sessions I concentrated on getting all of those supporting pylons for the MRGB in place. There are of course more pylons for the flotation gear involved in that area later on but by this point of the design/build you're having to work out not just designing parts of the helicopter but at the same time mentally creating an assembly sequence in your head that will allow all these parts to be assembled later in a feasible sequence.

 

My ideas for the pylon sequence evolved - as much of this way of working does - over the course of designing the parts and you become steadily more familiar with their relationships to one another in space.

 

Constructing the basic pylon wasn't hard (it's effectively the same item modified for different situations after all) so after studying the part(s) in question for a while I came up with this basic starter-template that could be ccopid and modified to build the other pylons:

Simple enough.

 

The hard part kicks in when you have to replicate these around the structure at a variety of angles which absolutely must match the required angles at the top on the MRGB and at the bottom on their respective mounting lugs. The good thing about CAD work is that you only have to build the pylons for one side of the helicopter and then you can mirror these across. The bad thing about it is that the symmetries involved will be bitterly cruel to any of the angles which are wrong to any appreciable degree.

 

Rather than trying to juggle all the balls at once, I concentrated on the rear set of MRGB pylons first, where they meet the three-way mounting post:

I mentioned about evolving ideas earlier and here, although I had initially intended the pylons and posts to be separate parts that could be locked together with brass pins, even at 1/24 those parts would be so thin individually that I've eelected now to print them as a combined structure for strength. This decision inevitably led to other - in a positive sense - discoveries as it helped me rationalize  an effective assembly sequence:

 - one allowing the MRGB to be slotted into position on the engine desk in one go as a fully supported structure.

 

Broadly similar but of a somewhat more complex set of orientations is the forward set of pylons. I initially thought that like the rear set,  there were just two of them to worry about. As you can see here though a closer inspection of shots taken from inside the cabin (with its rear central recess removed) as well as a particularly fine drawing in the manual quickly made me aware of the presence of a third pylon mounting front centre of the gearbox:

This fresh ( for which read 'there all the time if I'd been paying attention') information required me to go back and correct the design of the front of the gearbox to include the mounting for this third pylon:

Odd set of shapes that will be explained later when you see the pylon angle.

 

Front and rear pylons for one side nearly completed:

Not forgetting the 'outrigger' on the rear set that runs out the edge of the desk:

The front set of pylons completed - you can see below the addition of a mounting point that will enable this part to be located firmly and accurately against the gearbox:

 - whilst at the top the more robust mounting points on the pylons can slip ito position on either side of the brackets around the tp of the gearbox:

As per my original idea, such pylons can be locked into place on the MRGB at the top of using metal pins for strength.

 

At this point the assembly does rather look as if it should be testing the lunar regolith some time in about 1967...

 

Seen from the 'about to be ex-seagull by rotor blade' view you can see why getting all those angles drove me mad:

Also added at the back to test assembly sequence is the front mmountng of the ECU and its mini ski-jumps:

After make-up:

 

 

In fact the designs for this scale have already acccumulated more detail than previously on the Vixen:

So much so in fact that I'm beginning to experience Fusion  crashing more readily than usual due to the size of the project in RAM - it definitely doesn't like sharing memory with too many other programs open at the same time so much like I had to on the Vixen, I'm on the cusp here of having to break future work down into smaller projects that focus on just one area alone, which means I won't be able to do so many ensemble renders like this quite soon:

 

I don't know whether to continue in a rod vein and work on the servo systems for cyclic and collective (as this would inevitably involve moving on to the rotor head) or to return to the engine and finish adding all the required bits to it.

 

Might make more sense to get the engine done and then move forward from it to rotor...

 

Thanks for stopping by, I hope your weeks have been good to your so far.

Tony

 

 

 

 

 

 

[perdu]

Super.

 

Have you any idea whether a business package for fusion would help keep it manageable Tony?

 

Or is it down to your available RAM?

[giemme]

1 hour ago, TheBaron said:

At this point the assembly does rather look as if it should be testing the lunar regolith some time in about 1967...

Exactly my thought...

 

See, my analogy with the Millennium Falcon wasn't that far off, after all....  

 

Ciao

[Pete in Lincs]

It's certainly out of this world!

[Brandy]

I've had regular problems with Fusion not responding, then crashing, even with the small assemblies I've been working on. I usually have Spotify running at the same time though, so maybe that's the issue.

Hopefully it will allow us to see these renders for a while yet!

 

Ian

[wellsprop]

Crikey.

[perdu]

Tony I exhorted Mike to hunt around the Helicopter museum for us in the hunt for this secretive component

 

His words of wisdom

 

 

'The Rotor Brake Mounting, a cast-metal component, is bolted to the engine block. The part where the caliper bolts to it looks (shown in the upper cutout on the disc) is also disk like and is situated immediately behind the brake; hence why it is so hard to see it.'

 

Pictures too, thanks Mike.

 

 

 

 

 

As that is fairly clear I am just sitting back now enjoying the miracles from your Fusipen